From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ed1-f73.google.com (mail-ed1-f73.google.com [209.85.208.73]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5EE9E34753A for ; Mon, 22 Jun 2026 18:49:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.208.73 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782154154; cv=none; b=WdYipZNYFc8dBmZ9/liTo0NKNSqad6FY4xMzELKJTEnXnfMh2X9O6rqhHf1/68wZLdPFjx/s3WOV4vlLBsy9YVXprJ5j5NXXbAxLbDKpJCweG4hOyYc/x3S8KDh9XzlsOIRhbWjVQtgLBAkCE2gXhSRTeWEHZF3E/baDEy0Ek7M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782154154; c=relaxed/simple; bh=eSsWjg7+Xo0AyadgQytCuqK0tjsGOi6I8g06Sl8yFn4=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=sx5Sz2QBixlrv/RCnEHwpqBRwkIV9tCoY3Svy8pLrctIZv+z7VHKh9XgasDRLgV1Lcu/aCK0dE2KIBMhDOGJwJ8rU4YpgunHhBNHlYww2sJROq1WEE5WKL1OxRIyYmwUQD44m+PSMbXzGDJE6PopMQg+/6pTDQwuhhBVN1iKKcU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--tarunsahu.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=u7eXFR4i; arc=none smtp.client-ip=209.85.208.73 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--tarunsahu.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="u7eXFR4i" Received: by mail-ed1-f73.google.com with SMTP id 4fb4d7f45d1cf-697bd22237dso1143771a12.2 for ; Mon, 22 Jun 2026 11:49:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1782154145; x=1782758945; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=vrCK2iLTFuPkCKKXsEtILhMjhO8cYkJcRVq4TpiCh/Y=; b=u7eXFR4i9Xzw5O+9U+9FegGZfV5ObPFeB+fziH1eAPW7iDSiZoVnuS2MUVTGeRht6Q Fxb8xOzJFboveSoJapPHPpZnWXc2nvECkvqXK22QrWb3kpzAw7dfbCb1zd/+hVvprwl+ iysGW5dB0CJMjrHWnY97EQm3kwh9D5O8bwnG4GL0Wb53C16FRYL0sy/vgh8hVV00xwl8 Fqg6M6lWvfx8yntkF5Kvo5Ls9NX6Z1dXOBCFptjZKYcq1KlJXbRmmSY+VM3tZ27Fbn2/ ILg89W3QVd2BbRdjuBpDbfQlqAcCYBUA6vCvjbNInyLZ2LKT5YRwV2G+gtmsSTSSCh1v Sl1A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1782154145; x=1782758945; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=vrCK2iLTFuPkCKKXsEtILhMjhO8cYkJcRVq4TpiCh/Y=; b=amwaaYg4kYfjkfGz2ps5nZJwwnmKG0hZLpVEsFvbAmVB2RjfkDZIwg4e5+0u9QulwG G5qhZLZKcjSOLPH5LJpl3/fHla4TFBMo7/DNTFJiQFFTdKaLeeGMhHKCyy16nGf5GZ4+ eZH/5iaEXtjEJU/yHYKCBqksr6PstKHzXQLUsyVYNUBv6hRFxR16ENPmrzQ7V6pRmMu0 oj8spFGFJB4CC7VGfKLPcvJsouPMFHoutYOT/Tzhq5hdhJMEF1UVIkCj0Fh5f7i2qnUJ U52sE6bHSgcbum00Xm2/8bKB2kPfxh2onI/yUhDQ2tffrXkLlYEZ1Uor6yYCgscPfqdA liTA== X-Forwarded-Encrypted: i=1; AFNElJ9yqkErfswuaVeKhXBtjfgspSMalX7VP9tKGM8npjtzHFqT84VpADrXAMtHhlNUx32Cm0eGqwPflHQ2UqU=@vger.kernel.org X-Gm-Message-State: AOJu0Yzv60kR5k+72TlcLKcXwbVmBlXFXpf6HwSdukKdbQ9uF8uYE6O7 IUgrptnQZPpwHPz+E/A4+zDZG5D1OFfRPttkiqit2CGjm5qY3MEmJD5b9UW3B3ZXabC+Ox38MfE wh9bDVhBkR+RrmPl4Sw== X-Received: from edsl17.prod.google.com ([2002:aa7:d951:0:b0:695:f6a4:adb4]) (user=tarunsahu job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6402:35ca:b0:697:bd1d:116d with SMTP id 4fb4d7f45d1cf-697bd1d14acmr2221698a12.27.1782154145133; Mon, 22 Jun 2026 11:49:05 -0700 (PDT) Date: Mon, 22 Jun 2026 18:48:46 +0000 In-Reply-To: <20260622184851.2309827-1-tarunsahu@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260622184851.2309827-1-tarunsahu@google.com> X-Mailer: git-send-email 2.55.0.rc0.786.g65d90a0328-goog Message-ID: <20260622184851.2309827-5-tarunsahu@google.com> Subject: [PATCH v3 4/9] kvm: guest_memfd: Move internal definitions and helper to new header From: Tarun Sahu To: Jonathan Corbet , Mike Rapoport , Paolo Bonzini , Alexander Graf , Shuah Khan , Pratyush Yadav , Tarun Sahu , Pasha Tatashin Cc: kvm@vger.kernel.org, linux-mm@kvack.org, kexec@lists.infradead.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" To support guest_memfd memory preservation with LUO, guest_memfd luo code needs to access guest_memfd internals and reconstruct guest_memfd file instances from a preserved state. Extract gmem_file, gmem_inode, and the GMEM_I() helper from guest_memfd.c into a new internal header virt/kvm/guest_memfd.h. Additionally, split __kvm_gmem_create() to expose a non-static __kvm_gmem_create_file() helper. This helper returns a struct file instead of a file descriptor, enabling file creation and initialization without installing it into a file descriptor table. Signed-off-by: Tarun Sahu --- virt/kvm/guest_memfd.c | 68 +++++++++++++++++------------------------- virt/kvm/guest_memfd.h | 39 ++++++++++++++++++++++++ 2 files changed, 67 insertions(+), 40 deletions(-) create mode 100644 virt/kvm/guest_memfd.h diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c index 8669068..fe1adc9b 100644 --- a/virt/kvm/guest_memfd.c +++ b/virt/kvm/guest_memfd.c @@ -7,38 +7,12 @@ #include #include #include +#include "guest_memfd.h" #include "kvm_mm.h" static struct vfsmount *kvm_gmem_mnt; -/* - * A guest_memfd instance can be associated multiple VMs, each with its own - * "view" of the underlying physical memory. - * - * The gmem's inode is effectively the raw underlying physical storage, and is - * used to track properties of the physical memory, while each gmem file is - * effectively a single VM's view of that storage, and is used to track assets - * specific to its associated VM, e.g. memslots=>gmem bindings. - */ -struct gmem_file { - struct kvm *kvm; - struct xarray bindings; - struct list_head entry; -}; - -struct gmem_inode { - struct shared_policy policy; - struct inode vfs_inode; - struct list_head gmem_file_list; - - u64 flags; -}; - -static __always_inline struct gmem_inode *GMEM_I(struct inode *inode) -{ - return container_of(inode, struct gmem_inode, vfs_inode); -} #define kvm_gmem_for_each_file(f, inode) \ list_for_each_entry(f, &GMEM_I(inode)->gmem_file_list, entry) @@ -557,23 +531,17 @@ bool __weak kvm_arch_supports_gmem_init_shared(struct kvm *kvm) return true; } -static int __kvm_gmem_create(struct kvm *kvm, loff_t size, u64 flags) +struct file *__kvm_gmem_create_file(struct kvm *kvm, loff_t size, u64 flags) { static const char *name = "[kvm-gmem]"; struct gmem_file *f; struct inode *inode; struct file *file; - int fd, err; - - fd = get_unused_fd_flags(0); - if (fd < 0) - return fd; + int err; f = kzalloc_obj(*f); - if (!f) { - err = -ENOMEM; - goto err_fd; - } + if (!f) + return ERR_PTR(-ENOMEM); /* __fput() will take care of fops_put(). */ if (!fops_get(&kvm_gmem_fops)) { @@ -612,8 +580,7 @@ static int __kvm_gmem_create(struct kvm *kvm, loff_t size, u64 flags) xa_init(&f->bindings); list_add(&f->entry, &GMEM_I(inode)->gmem_file_list); - fd_install(fd, file); - return fd; + return file; err_inode: iput(inode); @@ -621,7 +588,28 @@ static int __kvm_gmem_create(struct kvm *kvm, loff_t size, u64 flags) fops_put(&kvm_gmem_fops); err_gmem: kfree(f); -err_fd: + return ERR_PTR(err); +} + +static int __kvm_gmem_create(struct kvm *kvm, loff_t size, u64 flags) +{ + struct file *file; + int fd, err; + + fd = get_unused_fd_flags(0); + if (fd < 0) + return fd; + + file = __kvm_gmem_create_file(kvm, size, flags); + if (IS_ERR(file)) { + err = PTR_ERR(file); + goto err_put_fd; + } + + fd_install(fd, file); + return fd; + +err_put_fd: put_unused_fd(fd); return err; } diff --git a/virt/kvm/guest_memfd.h b/virt/kvm/guest_memfd.h new file mode 100644 index 0000000..c528b04 --- /dev/null +++ b/virt/kvm/guest_memfd.h @@ -0,0 +1,39 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef __KVM_GUEST_MEMFD_H__ +#define __KVM_GUEST_MEMFD_H__ 1 + +#include +#include +#include + +/* + * A guest_memfd instance can be associated multiple VMs, each with its own + * "view" of the underlying physical memory. + * + * The gmem's inode is effectively the raw underlying physical storage, and is + * used to track properties of the physical memory, while each gmem file is + * effectively a single VM's view of that storage, and is used to track assets + * specific to its associated VM, e.g. memslots=>gmem bindings. + */ +struct gmem_file { + struct kvm *kvm; + struct xarray bindings; + struct list_head entry; +}; + +struct gmem_inode { + struct shared_policy policy; + struct inode vfs_inode; + struct list_head gmem_file_list; + + u64 flags; +}; + +static inline struct gmem_inode *GMEM_I(struct inode *inode) +{ + return container_of(inode, struct gmem_inode, vfs_inode); +} + +struct file *__kvm_gmem_create_file(struct kvm *kvm, loff_t size, u64 flags); + +#endif /* __KVM_GUEST_MEMFD_H__ */ -- 2.55.0.rc0.786.g65d90a0328-goog